The Gaia-ESO Survey: Low-α element stars in the Galactic bulge⋆

Author： Recio-Blanco A.   Rojas-Arriagada A.   de Laverny P.   Mikolaitis S.   Hill V.   Zoccali M.   Fernández-Trincado J. G.   Robin A. C.   Babusiaux C.   Gilmore G.   Randich S.   Alfaro E.   Allende Prieto C.   Bragaglia A.   Carraro G.   Jofré P.   Lardo C.   Monaco L.   Morbidelli L.   Zaggia S.  

Publisher： Edp Sciences

E-ISSN： 1432-0746|602|issue|L14-L14

ISSN： 0004-6361

Source： Astronomy & Astrophysics, Vol.602, Iss.issue, 2017-06, pp. : L14-L14

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

We take advantage of the Gaia-ESO Survey iDR4 bulge data to search for abundance anomalies that could shed light on the composite nature of the Milky Way bulge. The α-element (Mg, Si, and whenever available, Ca) abundances, and their trends with Fe abundances have been analysed for a total of 776 bulge stars. In addition, the aluminum abundances and their ratio to Fe and Mg have also been examined. Our analysis reveals the existence of low-α element abundance stars with respect to the standard bulge sequence in the [α/ Fe] versus [Fe/H] plane. Eighteen objects present deviations in [α/ Fe] ranging from 2.1 to 5.3σ with respect to the median standard value. Those stars do not show Mg-Al anti-correlation patterns. Incidentally, this sign of the existence of multiple stellar populations is reported firmly for the first time for the bulge globular cluster NGC 6522. The identified low-α abundance stars have chemical patterns that are compatible with those of the thin disc. Their link with massive dwarf galaxies accretion seems unlikely, as larger deviations in α abundance and Al would be expected. The vision of a bulge composite nature and a complex formation process is reinforced by our results. The approach used, which is a multi-method and model-driven analysis of high resolution data, seems crucial to reveal this complexity.

Related content

The Gaia-ESO Survey: Exploring the complex nature and origins of the Galactic bulge populations⋆

By Rojas-Arriagada A.   Recio-Blanco A.   de Laverny P.   Mikolaitis Š.   Matteucci F.   Spitoni E.   Schultheis M.   Hayden M.   Hill V.   Zoccali M.   Minniti D.   Gonzalez O. A.   Gilmore G.   Randich S.   Feltzing S.   Alfaro E. J.   Babusiaux C.   Bensby T.   Bragaglia A.   Flaccomio E.   Koposov S. E.   Pancino E.   Bayo A.   Carraro G.   Casey A. R.   Costado M. T.   Damiani F.   Donati P.   Franciosini E.   Hourihane A.   Jofré P.   Lardo C.   Lewis J.   Lind K.   Magrini L.   Morbidelli L.   Sacco G. G.   Worley C. C.   Zaggia S.  

Astronomy & Astrophysics, Vol. 601, Iss. issue, 2017-05 ,pp. : A140-A140 (NaN)

Edp Sciences

Access to resources Recommend Favorite

The Gaia-ESO Survey: α-abundances of metal-poor stars

By Jackson-Jones R.   Jofré P.   Hawkins K.   Hourihane A.   Gilmore G.   Kordopatis G.   Worley C.   Randich S.   Vallenari A.   Bensby T.   Bragaglia A.   Flaccomio E.   Korn A. J.   Recio-Blanco A.   Smiljanic R.   Costado M. T.   Heiter U.   Hill V.   Lardo C.   de Laverny P.   Guiglion G.   Mikolaitis S.   Zaggia S.   Tautvaišienė G.  

Astronomy & Astrophysics, Vol. 571, Iss. issue, 2014-11 ,pp. : L5-L5 (NaN)

Edp Sciences

Access to resources Recommend Favorite

Hot stars in the Gaia-ESO Survey

By  

Journal of Physics: Conference Series , Vol. 328, Iss. 1, 2011-12 ,pp. : 157-164 (8)

IOP Publishing

Access to resources Recommend Favorite

The Gaia-ESO Survey: Galactic evolution of sulphur and zinc⋆⋆⋆

By Duffau S.   Caffau E.   Sbordone L.   Bonifacio P.   Andrievsky S.   Korotin S.   Babusiaux C.   Salvadori S.   Monaco L.   François P.   Skúladóttir Á.   Bragaglia A.   Donati P.   Spina L.   Gallagher A. J.   Ludwig H.-G.   Christlieb N.   Hansen C. J.   Mott A.   Steffen M.   Zaggia S.   Blanco-Cuaresma S.   Calura F.   Friel E.   Jiménez-Esteban F. M.   Koch A.   Magrini L.   Pancino E.   Tang B.   Tautvaišienė G.   Vallenari A.   Hawkins K.   Gilmore G.   Randich S.   Feltzing S.   Bensby T.   Flaccomio E.   Smiljanic R.   Bayo A.   Carraro G.   Casey A. R.   Costado M. T.   Damiani F.   Franciosini E.   Hourihane A.   Jofré P.   Lardo C.   Lewis J.   Morbidelli L.   Sousa S. G.   Worley C. C.  

Astronomy & Astrophysics, Vol. 604, Iss. issue, 2017-08 ,pp. : A128-A128 (NaN)

Edp Sciences

Access to resources Recommend Favorite

The Gaia-ESO Survey: radial distribution of abundances in the Galactic disc from open clusters and young-field stars⋆

By Magrini L.   Randich S.   Kordopatis G.   Prantzos N.   Romano D.   Chieffi A.   Limongi M.   François P.   Pancino E.   Friel E.   Bragaglia A.   Tautvaišienė G.   Spina L.   Overbeek J.   Cantat-Gaudin T.   Donati P.   Vallenari A.   Sordo R.   Jiménez-Esteban F. M.   Tang B.   Drazdauskas A.   Sousa S.   Duffau S.   Jofré P.   Gilmore G.   Feltzing S.   Alfaro E.   Bensby T.   Flaccomio E.   Koposov S.   Lanzafame A.   Smiljanic R.   Bayo A.   Carraro G.   Casey A. R.   Costado M. T.   Damiani F.   Franciosini E.   Hourihane A.   Lardo C.   Lewis J.   Monaco L.   Morbidelli L.   Sacco G.   Sbordone L.   Worley C. C.   Zaggia S.  

Astronomy & Astrophysics, Vol. 603, Iss. issue, 2017-06 ,pp. : A2-A2 (NaN)

Edp Sciences

Access to resources Recommend Favorite